Light recording apparatus



KR ZaEBgEQQ B REZ- HO March 25, 1941. E, O D HAL 2,236,390

LIGHT RECORDING APPARATUS Filed March 26, 1938 2 Sheets-Sheet l INVENTOR5. F 250 E 14000 B H0200: Dflwsc/v cud, M, M a

ATTORNEYS.

March 25, 1941. F. E. woon ETAL LIGHT RECORDING APPARATUS 2 Sheets-Shet 2 Filed March 26, 1938 5 T R m mam wwwwm m9 w M M E 0 ENE R O H W w m Patented Mar. 25, 1941 7 I UNl'lED STATES Pram orrics r. LIGHT RECORDING APPARATUS Fred E. Wood, River Forest, and Horace Dawson, Evanston, Ill.

Application March 26, 1938, Serial No. 198,338

2 Claims. (Cl. 273-1011) This invention relates to light recording appaemployed and it is obvious that this means may ratus and method. take a large variety-of forms. The light flash or An object of the invention is to provide a new illumination may be formed by an incandescent method and means for recording upon a surface, bulb, a flash bulb of the type used in photoat least for a limited period of time, a spot or graphic methods, a mercury light, an are light, area of light. A further object is to provide a alight formed by combustion of powder or other luminous surface which will reproduce and main materials, etc. For the purpose of illustration, tain for a period of time the contour of a light we have shown but one means for forming the spot or line, the surface being illuminated nordesired light beam.

10 mally with light rays which do not, in any sub- In the illustration given, the light shooting 10 stantial degree, excite or activate the surface. A device A comprises a frame It], generally in the further object is to provide a light recording surform of rifie- It Will be dQIfS OOd that the face with means for briefly forming a light area frame a be in t form f a p st i-r v ver, or

thereon, the record of said light area being transiy o r Suitable desired s pe 1 formn tory. A still further object is to provide a target the frame 10 there"is suppo tc hfim l llv D having a light-activatable surface, together with vided at its rear side with a closure member 12 means for flashing a spot of light upon the target hrough the central part of which is formed a whereby the spot is recorded and made visible in minute p n n actual pr the op nits outline for a period of time. A further object mg 13 s much smaller than that shown in the is to provide improved mechanism for shooting d s, the 01 be eXaggelated in the draW- from a distance an intensified beam of light upon s for the purpose of illustration. In the for- L a light-responsive target, said light shooting ward end of the barrel H is mounted a thin means being adjustable for changing the time or inner b el He a i a s M which y be ex osure, changing the area, and ont f th of any suitable form or construction for directing light area, and in various other ways affecting the light rays to form an object of a desired conthe characteristics of the light flash and means he particular lens illustrated is so corof forming the same. Other specific objects and related with the opening 3 a d W e length advantages will appear as the specification prof t e S OPE 0 t OW a Small Sp O light so e s ceeds. thirty feet away.

" The invention is illustrated, in a preferred em- In the spec fic illustration n, the two-p 30 bodiment, by the accompanying drawings, in lens shown is secured in position within tube H which by means of a threaded collar l5 and a slight Figure 1 is a side view in elevation of the light shoulder in tube indicated by the numeral l6. shooting device, the target, and illuminating de- It will be understood that the lens M may be Vice illustrating our invention; Fig. 2, a longimodified in shape and structure in agreat variety tudinal sectional view of a portion of the light of ways so as to produce a spot of light at a shooting device; Fig. 3, a broken longitudinal desired distance or an area of light of any desectional view of the telescope barrel; Fig. 4, a sired contour. Secured to the lower part of the transverse detail sectional view, the section being barrel by Spot Welding, Screws, 0 other Suittaken as indicated at line 4 of Fig. 2; Fig. 5, an able means, is a rack l1 extending through a 40 3 enlarged detail view in elevation of means assolongitudinal slot in barrel H and which is enciated with the trigger for actuating the shutter; gaged by a toothed wheel l8 accessible through Fig. 6, a longitudinal sectional view of the strucan opening in the forward part of easing I0. By ture shown in Fig. .5; Fig. 7, a longitudinal secuse of a small instrument, the wheel l3 can be tional view of the timing device employed; and rotated so as to shift the lens closer to or away Fig. 8, a broken transverse sectional View of the from the aperture so as to permit proper form target or light recording device employed. of spot of light when shooting from varying dis- In the illustration given, A designates a light tances. shooting device; B, a light recording device; and In the illustration given, We prov d a ght 5i) C. an illuminating device. bulb supD 49 j behind the rear Portion of 50 The device for throwing the light spot may be barrel II, the support being secured upon the a of any suitable construction. Any means for bracket 20' carried by casing The pp l9 creating a light of sufilcient intensity and for is provid d W th a d wnwardly extendin Screw directing the beams therefrom so as to form a ll threadedly engaging the knurled nut 22. spot or light area of the desired contour may be Preferably, the reduced shank 23 of the bulb support l9 is-slidably carried within a sleeve 24 carried by the bracket 20, the reduced shank 23 being square in shape and being received within a square tube 24. Rotation of the nut 22 thus raises or lowers the support [9 depending upon the direction of rotation of nut 22. Frame 26] can be moved from side to side on swivel as. Friction holds it in place.

The light source illustrated is an electric light bulb 25. The bulb is secured within the mounting or holder IS with the usual bayonet lock connection whereby the light bulb may be rotated a partial revolution within the holder i9 while yet making contact. Also, the holder 19 can be rotated upon shank 23. We prefer to rotate the light bulb 25 so as to bring the two posts of the loop filament thereof almost in line with the opening l3 in member l2. The two strands are, however, slightly out of alignment so that the direct rays from both posts pass directly into the opening 13, thus filling the opening l3 with light. The light filament 2B is shown more clearly in Figs. 2 and 4. With the structure shown, the light bulb 25 may be rotated while maintaining its contact, while at the same time the entire supporting structure may be raised or lowered b manipulation of nut22 and moved sideways by rocking frame 23 on swivel 89, all of which movements permit proper alignment of the filament posts and. aperture l3. Above bulb 25 is a swiveled closure 81 which may be opened to provide access to bulb 25.

Any suitable means may be employed for permitting the light rays to pass through the opening l3. If desired, the opening l3 may be left unprotected and the light beam caused by simply turning current on and off so as to flash the bulb 25. We prefer, however, to illuminate bulb 25 before permitting the light rays to pass therefrom through opening'lS, thus building up the intensity of the bulb to its highest point at the time the rays are permitted to be passed through opening i3. In the illustration given. this is accomplished by meansnof a shutteril. which is pivotally supportedtobracket 28 .at the point ZBJThe shutter is cut away at its upper face as indicated by the numeral 39, one portion of the shutter, however, entirely covering the opening I3. The lower portion of shutter 2'! is provided with an extension 3| which is engaged by a spring 32 normally urging the shutter to the left, as viewed in Fig. 4. Movement to the left, is, however, prevented by an actuating finger 33 of a sector member 34 which extends substantially at right angles to the shutter 21. The shutter 2! is provided with a cam surface 35 which is en gaged by the sector member 3%...when the same is swung upwardly so'afs t'o swing the shutter 21 to the right, as viewed in Fig. 4, thus exposing the opening l3 to the rays of light from lamp 25. As shown more clearly in Fig. 4, the sector member 34 is pivoted upon shaft 3-8 secured to one wall of the frame It). A spring 37 is secured to frame [9 and to the lower portion of sector 34, as shown more clearly in Fig. 2, so as to draw the lower part of the sector 3 to the left, as viewed in Fig. 2. For actuating the shutter, it is necessary to draw the sector 34 rearwardly against the force of spring 31, and this is accomplished through the medium of the long link arm 38.

The link arm 38 is pivotally connected to the lower end of lever 39 which is in turn pivoted upon frame 19. The upper end of lever 39 is provided with a trigger notch 42. Notch 451 is adapted to be engaged by a shoe member ll urged downwardly by spring 42, the spring being carried by the slide rod :33, and the shoe member t! being also pivoted upon the slide rod The slide rod 63 is provided with a pin A l which engages slots 5 in a hammer 25. The hammer iE is pivoted at its lower end portion at 45, and the detent 47 extending from the lower portion thereof engages the trigger it in a well known manner, the trigger being provided with the locking notch In 10 the illustration given, the stock portion of the frame 53 is provided with a slot 53 receiving the rear portion of the rod or plunger member 23. and the rod is guided by an apertured boss 52 carried by frame l9.

If desired, suitable means be pro controlling the movement of rod I tration given, we have provided a dashes ing device consisting of a tube into w position. At the opposite end of the to head member threadedly '1 t the tube and closing the same,

provided with a threaded extension receivin the screw 57, screw 5? being carried by tl rotatable or adjustment disk formed of felt or other suitable i trally apertured to receive the threaded c sion of head 55 and assists in controlling L19 release of air from the tube. When the disk 52 is screwed out partially, the expanding felt 59 permits air, which passes around the threaded screw escape rather freely, but when the screw 58 is extended inwardly, the felt as is compressed and air escapes less freely. The knurled disk E3 is exposed within a slot 59 formed in frame if whereby the operator may adjust the device from the exterior of the gun. The trigger s3 is provided with a spring 8: which normally draws it toward the position shown in Fig. l.

The lever 39 and shoe ii are preferably guided within a channel bracket 6-2 which is slotted at 63 in its lower wall to permit the projection 3-3 of lever 39 to extend therethrough.

Any suitable switch arrangement for illuminating the bulb 25 may be employed. In the illustration given, we provide a fixed contact member 64 at the top of the frame, and spaced forwardly of the contact 84 is a second insulated support 65 carrying a depending spring finger E3, the spring of the finger normally drawing it forward into contact with the member 6 3 to close the circuit. The spring 64 has a bottom extension which is adapted to be engaged by an insulated block or ledge 51 secured to the top of the rod or plunger 43. When the rod is in the position shown in Fig. l, the ledge 87 holds spring 55 out of engagement with contact 64. However, when the hammer 55 is retracted, the member 61 is drawn back and permits the contact to be formed. Suitable wire connections (not shown) form a circuit with the light bulb whereby illumination of the bulb is produced when the contacts 66 and lid come together.

In the operation of the specific form of light projecting device illustrated, the hammer 4.5 is first drawn rearwarclly and thus by engagement with pin 4-1 retracts the plunger 5-3 against the force of the spring 55 in the tube 52. This movement draws the shoe member 41 back of the lever 39 so that it is in position to operate lever 39 when the plunger moves forwardly. At the same time, the lower extension 5'! of the hammer 45 engages the trig er shoulder 49 and thus holds the hammer 45 in retracted position. At the same time, the rearward movement of the ledge 61 permits the spring contact 66 to engage the contact 54, thus closing the circuit and illuminating the light bulb 25. When the trigger is pulled, the hammer 45 is released and the plunger 43 is drawn forwardly by spring 55. As the plunger moves forwardly, it carries the shoe l which engages the extension 40 of lever 39 swinging the top part thereof forwardly. This draws the long link member 38 in a rearward direction and tilts the sector 34 so that the operating extension 33 thereof engages the cam surface 35 of the shutter-21 and swings it laterally against the force of spring 32. The lateral movement of shutter 21 exposes the opening l3 in the tube H so thatlight rayspass from the two filament posts through the opening and are directed by the lens so as to form a. tiny spot on the target some distance away. As the rod 43 moves forwardly, the speed movement being regulated by the passage of air from tube 52, the shoe member 5| finally trips over the extension 40 of lever 39 whereby lever 39 springs back to its initial position under the force of spring 31 secured to the lower end of sector arm 34 carrying the extension link 38. This movement releases shutter 27, and under the force of spring 32, it springs back to its initial position over the opening l3,

It will be seen that the period of exposure of the light beam is controlled by the knurled disk 58, which in turn controls the escape of air from the tube 52. As already stated, the light bulb 25 may be adjusted vertically by means of the knurled disk 22 and may be rotated slightly within its socket while still making contact therein, so that the two post portions of the loop filament are almost in line with the opening, the two posts being slightly out of alignment whereby light rays from both pass through the opening. Also, adjustment of the lens with respect to aperture I3 is accomplished by rotating the toothed wheel it which engages the rack IT. A stop 82 holds lever 39 normally against the force of spring 37.

In setting out one means for projecting a light ray of high intensity, it is realized that such means is only one of a great number of apparatuses effective for this purpose. The intensity of the beam being projected and the projection thereof, the timing of the flash, various adjustment means operating in such apparatus, may obviously be varied extensively. The purpose of the disclosure herein is to set forth one complete device for the purpose of illustration.

By using a light source giving an intense beam, and a filter therewith which permits only rays which activate the luminous surface to pass through, such rays being within the visible or invisible portion of the spectrum, the luminous surface will respond markedly to such rays while responding in a much lesser degree and, by contrast; hardly noticeable degree to ordinary light illumination. Aviolet or ultra-violet light bulb, etc., such as illustrated, may be used.

The light recording device B may be of any suitable construction. In the illustration given, we provide a target sheet 68 received within a box casing 69 equipped with a hinged closure 10. When not in use, the hinged cover is kept closed to protect the target from exposure to light. In the illustration given. the target consists of a cardboard backing ll having preferably a white surface provided with a luminous surfacing layer '12.

One seemingly insurmountable difliculty of using a luminous surface for recording a light where it is desired that the surface itself be clearly visible, is that the light which is used to illuminate the target also activates it, with the result that the entire surface glows. Thus when a beam of light is thrown upon the target, it is difficult to form a record of the light unless the'beam is of extreme brilliance. We have found that luminous surfaces may be employed which are selective in character; that is, they are not activated to any considerable extent by certain types of light rays while they are extremely sensitive and responsive to activation I by other light rays. For example, we find that certain luminous paints when spread over a sur-- face, such as H, in combination with a clear lacquer, are not excited to any very noticeable degree by red or green rays when the source of the light is several feet from the target, while they are extremely sensitive and are readily excited by other light rays. Such luminous compounds are well known and are in commercial use. As examples, the sulphides of barium, calcium, zinc and strontium, containing as usual some impurities, will continue to glow after the removal of the illumination. The sulphide powders, combined with a colorless lacquer, are applied to the surface of the cardboard backing H. Any suitable markings may be formed on the target by using one of the powders for the background and another of the powders for forming the demarcation lines; or, if desired, a black or other colored lacquer may be used. Where a target is formed, as shown in the illustration, the lines '13 may be formed by using a sulphide powder which is different in color from the particular powder used to form the backing surface or, if desired, a. black lacquer, etc., may be employed for this purpose. The several sulphides above mentioned differ in color so that one may be employed in contrast with another or with the others for forming a continuous luminous surface with designs formed thereon in different colors. In view of the fact that luminous surfaces of many types having the properties of glowing after the removal of the illumination are Well known, no attempt will be made to exhaustively cover all of such types, it being sufiicient to state that they are well known in the art. It will be observed that the bulls eye of the target is provided with luminous paint for recording light spots thereon.

As already stated, we utilize the selective characteristics of the luminous surfaces for effecting an illumination of the object, with one type of ray to which the'target is not noticeably responsive, while forming by contrast the light spot or area on the surface by means of another source of illuminatoin which includes rays to which the luminous surface is readily responsive. Further, a dim light containing activating rays may be employed, while using an intense beam containing activating rays for forming the light spot which stands out in contrast to the feeble activation of the entire surface. We find that the powders are not normallyexcited to any great extent by the rays of longer Wave length. For example, red light and green light do not excite the powders to any noticeable extent. Green excites luminosity but the degree is relatively small. Likewise certain shades of red,'but slight excitation does not interfere,

However, lights having great actinic powersreadily excite the surface. Ultra-violet rays and rays of short length cause the surface to glow actively after avery-brief illumination therewith. White light containing the rays of short wave length activates the surfaces.

Under strong light containing rays of short wave length, the better powders will be activated or excited instantaneously so that an exposure of but a fraction of a second will bring about phosphorescence. Apparently the longer the exposure to light, the longer will phosphorescence last. Short exposures, as where a spot is formed on the target for a brief moment result in a glow lastingfrom a minute to several minutes. Exposures lasting four or five minutes result in phosphorescence for several hours. With brighter beams and rays of greater power of activation, the duration is longer.

An interesting characteristic of the luminous surface is that there seems to be practically no tendency for the glowing portion to diffuse into the unexcited portion of the surface; that is, the excited portion will not, in turn, excite the unexcited portion.

For excluding as much as possible light beams from various sources and for the purpose, as shown later, of flooding the target with a particular colored ray, we prefer to enclose the target within a box or casing. If desired, the box may be quite deep so that light from the side is entirely excluded. We obtain good results by placing the target in the back end of a tube lined with black felt, the tube then being illuminated by a window (not shown) having a red filter and with a light bulb above the filter.

By flooding the target with a colored ray, such as red or, from a distance, green, which has little tendency to excite a glowing effect, we find that ample illumination of the target is produced, while at the same time the target is directly responsive to white light or any combination of light including rays of short wave length so that spots formed by such light are immediately recorded by a glowing area on the target, the glowing area being coterminous with the light spot formed. Any suitable means for forming such illumination may be employed. In the simple apparatus illustrated, we provide a reflector 14 provided at its forward end with a color filter 15 of the desired color, such as, for example, red or green. The reflector is supported by a stand 16 and a light bulb TI is supported within the reflector casing.

It will be understood that by employing a very intense ray to which the target is extremely sensitive, a light spot may be formed thereon while yet illuminating the target with ordinary light. In other words, by using a luminous surface which is very responsive to an intense ray or a ra of a definite wave length, a record may be made because of the preferential response of the target to such a ray even though ordinary illumination be employed, Furthermore, if desired, the target may be placed in a substantially dark area, the outlines of the rings being formed by constantly luminous material, such as zinc sulphide mixed with radium, thus rendering the target lines visible in the dark.

In the operation of the specific illustrative apparatus disclosed, the target 68 is supported within the box 69 and illuminated by a ray of relatively long wave length, such as, for example,

ing a spot of light upon the target, the period of exposure being regulated as already outlined. A number of light spots ma thus be formed to form a target pattern. The spots will glow upon the target for a period of one to several minutes during which time the marksman may examine the group. By drawing a curtain about the target or otherwise darkening the target, the intensity of the light spots is increased. Thereafter, the light spots fade slowly away, becomin less and less distinct. We have found that the glowing light spots can be quickly quenched by bringing the red rays up to the target and passing the rays back and forth or in any way across the target. For example, we have taken a red light bulb and quickly quenched the light spots by passing the light bulb back and forth across the face of the target.

In the development of an intense light, we

sometimes emplo a transformer reducing the voltage to that suitable for a small light such as illustrated, the small bulb permitting the light filaments to be placed close to the opening. Some small automobile lamps which have been developed for use with parabolic reflectors form an intense light concentrated in a small area and having a large percentage of rays of short wave length which readily excite the luminous paint. By employing a higher voltage than that for which the tube is normally designed, we find that J;

a more intense light is produced and which is satisfactory, Photo flush bulbs form a large percentage of actinic rays or rays of short wave length and may be substituted for bulb 25. New

lamps have recently been developed to take the place of photographic flash bulbs and which These produce an extremely brilliant light. be used with the ordinary voltage employed in cities and it is merely necessar to have the wire leadin from the rifle or pistol, etc. provided with a connection for engaging a socket in the wall.

Instead of employing a light bulb which is clear or colored violet, ultra-violet, or other colors whereby, as already described, for projecting a ray or group of rays of a special wave length or a group of rays including short and long rays, as in the case of a clear bulb, it will be understood that any form of filter may be employed in conjunction with a clear bulb or other source of light. Furthermore, it is well known that certain sources of light emit rays of preponderantly short wave length which activate luminous surfaces to a great extent. Through the use of such extremely short rays or such rays as greatly it to any substantial degree and then project light spots containing activating rays upon the surface, or else We use the other alternative of illuminating a luminous surface which is not reactive to any appreciable extent with ordinary light or with rather mediocre illumination and then project upon such a surface rays which greatly excite ordinary illumination in their powor to excite luminosity in the surface.

In the preparation of the target surface or the light recording surface, we find that a surface layer can be prepared which is poorly responsive to light by using smaller quantities of the powders already described with greater quantities of lacquer, etc., or by using the powders which are least excited by light rays to luminosity. The variations and changes here involved will be recognized by those skilled in the art.

By shooting invisible rays, the operation more closely simulates actual shooting with a rifle,

since neither the bullet nor the ray are visible.

While in the foregoing specification, We have gone into details as to steps and means employed, it will be understood that these may be varied widely without departing from the spirit of our invention. The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

We claim:

1. In apparatus of the class described, a target member provided with a. surface layer excitable by certain rays of light to luminosity, means for illuminating said target to render the entire target surface visible to the eye by light rays which illuminate but do not substantially excite said surface to luminosity, and a light discharge means in the shape of a firing iron adapted to be held in the hands of the user at a spaced distance from said target for momentarily projecting a confined beard of rays of a type adapted to excite said layer to luminosity upon a spot on said target layer to cause said spot to become luminous against a non-luminous but visible target background.

2. In apparatus of the class described, a target member provided with a surface layer excitable by certain rays to luminosity but nonexcitable by certain illuminating rays, means for illuminating said surface layer to render it visible to the eye solely by. light rays which illuminate but do not substantially excite said surface to luminosity, and light projecting means adapted to be held in the hands of the user at a pre-determined distance from said target for projecting a concentrated beam upon a relatively small area upon said illuminated but non-excited surface, said concentrated beam consisting of rays which excite said small area to luminosity to render the same visible against a non-luminous background provided by the remainder of said surface layer.

FRED E. WOOD. HORACE DAWSON. 

